1. Technical Field
The invention relates to medical appliances, particularly to phlegm suckers.
2. Related Art
A conventional irrigator port 1a is shown in FIG. 1. The irrigator port 1a includes a tube body 10a and a tube connector 11a connecting to one end of the tube body 10a. A passage 110a is formed in the tube connector 11a and communicates with the tube body 10a. One end of the tube body 10a may be connected to a phlegm suction tube. The tube body 10a is provided with a check valve which flexibly closes the passage 110a for preventing phlegm from flowing back and allowing to inject chemical agents, such as cleaners and germicides, through the passage 110a. Usually, injecting chemical agents is performed by inserting a syringe into the passage 110a. 
However, the passage 110a of the coupling 1a can fit an injector with a specific single size. Usually, a diameter of the passage 110a is about 3.85 mm-3.90 mm. Those injectors with sizes other than this size cannot be fit. This causes a restriction of usability. Besides, the irrigator port 1a cannot be changed into another size.